Title Slide

Report
Results from UNSCEAR & ICRP Recommendations
South Africa -- 2009 April 15-17
Chris Clement
ICRP Scientific Secretary
 Why is radiological protection important in medical
exposures?
 The ICRP system of radiological protection in
medicine
2
3
 The highest source of artificial exposure, by far
Source
Global Average Dose
(mSv per year)
Occupational
0.005
Atmospheric Nuclear Testing
0.005
Chernobyl Accident
0.005
Medical Diagnosis
0.6
From UNSCEAR
 Average and collective doses increasing rapidly,
particularly due to increasing use of CT
4
5
6
Brain damage from
radiotherapy overexposure
Whole body of baby exposed
instead of chest only
Overheated X-ray tube stopped 18 months after cardiac cathetericardiac procedure
sation and stent placement
7
8
 P 103: the complete system of protection
 P 105: Radiological Protection in Medicine (replaces P 73)
 P 80: Radiation Dose to Patients from
Radiopharmaceuticals
 P 84: Pregnancy and Medical Radiation
 P 85: Avoidance of Radiation Injuries from Medical
Interventional Procedures
 P 86: Prevention of accidental exposures to patients
undergoing radiation therapy
9
 P 87: Managing Patient Dose in Computed





Tomography
SG 2: Radiation and your patient: A guide for medical
practitioners
P 93: Managing patient dose in digital radiology
P 97: Prevention of high-dose-rate brachytherapy
accidents
P 98: Radiation safety aspects of brachytherapy for
prostate cancer using permanently implanted sources
P 102: Managing Patient Dose in Multi-Detector
Computed Tomography (MDCT)
10
 P 106: Radiation Dose to Patients from
Radiopharmaceuticals
and in the works:
 Minimising unintended exposure in radiation therapy
from new technologies
 Evaluation and management of secondary cancer risk
in radiation therapy
 Protecting Children in Paediatric Radiology
11
Justification
 Benefit and most of the risk apply to the patient
Optimization
 ALARA in medicine is management of the radiation
dose to the patient commensurate with the medical
purpose
 Diagnostic reference levels (not constraints)
Dose Limitation
 Does not apply to medical exposures (of patients)
12
1.
Is the proper use of radiation in medicine doing
more good than harm to society?
2. A specified procedure with a specified objective
 e.g. chest x-ray for diagnostic purposes for patients
showing relevant symptoms
3. Application to a specific patient
 i.e. Do more good than harm to the patient
13
INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION
——————————————————————————————————————
INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION
——————————————————————————————————————
Maybe not all that bad...
 “responsible ... low-dose
screening”
 “targeted scans of vital
organs”
 “does not perform
unproven Full Body
Scans”
 “If you have risk
factors...”
16

Two levels of optimization:
1.
2.
The design, selection and construction of equipment
and installations
The day-to-day methods of working

Keeping doses ALARA, economic and societal factors
being taken into account

In medicine this is management of the
radiation dose to the patient commensurate
with the medical purpose
17
Doses can be too high
 Non-optimised diagnostic equipment or methods (e.g. QA
problems, limited access to, short-lived radiopharmaceuticals)
 Non-optimised therapeutic equipment or methods (e.g. limited
access to conformal therapy, inverse dose-planning)
 Inadequate or insufficient training (e.g. over-utilisation of ‘boost’
options in digital radiology)
Doses can be too low
 The UK Computerised Treatment Planning accident, 1982-1991
 1 045 patients affected, 5-30% under-dosage
 492 patients had a recurrence, believed to be caused by the
under-dosage
18
19
 Detriments and benefits are received by the same
individual, the patient
 Dose is determined principally by medical needs
 Dose constraints are therefore inappropriate
 Diagnostic Reference Levels help evaluate whether a
patient dose is unusually high or low for a particular
procedure
20
 The concept: are my doses in line with those of my peers?
 If not: Do I have a good reason?
 DRLs should be set by regional / national / local bodies
 One size does not fit all!
 DRL numerical values are advisory
 Implementation of the concept may be a legal requirement
 DRLs should be easily measured
 ESD, DAP, DLP, administered activity…
 DRLs apply to groups, not to single patients
21
22
 Alliance for Radiation Safety in Pediatric Imaging
(Society for Pediatric Radiology)
 www.imagegently.org
23
Christopher Clement CHP
Scientific Secretary
International Commission on Radiological Protection
PO Box 1046, Station B
280 Slater Street
Ottawa, Ontario K1P 5S9
CANADA
[email protected]
www.icrp.org
24

similar documents